Pregnant woman is monitored by nurse, based on the following image. Identify the wave pattern:

AIIMS Delhi NO- 2019

Obstetrics & Gynaecology

Hard

Appeared in: AIIMS Delhi NO- 2019

Explanation

The image shows a periodic, gradual drop in the fetal heart rate (FHR), which is defined as a deceleration.
Specifically, the pattern is an early deceleration, where the FHR drop creates a 'mirror image' of the uterine contraction pattern shown on the lower tracing.
The lowest point (nadir) of the heart rate dip aligns perfectly with the peak of the contraction, and the FHR returns to baseline as the contraction ends.
This pattern is caused by vagal nerve stimulation due to fetal head compression during a contraction and is considered a normal, reassuring finding during labor.

Option B: While early decelerations are considered a reassuring sign, 'Reassuring pattern' is a clinical interpretation or category, not the specific name of the wave form seen. The question asks to identify the pattern itself, which is a deceleration.
Option C: Fetal tachycardia is a sustained baseline FHR above 160 beats per minute (bpm). The baseline FHR in the image is within the normal range of 110-160 bpm (approximately 130-140 bpm).
Option D: A fetal acceleration is a temporary increase in the FHR from the baseline. The image clearly shows a temporary decrease (deceleration) in the FHR, not an increase.

Clinical Relevance

Nursing practice connection: Use the key finding related to Interpretation of Fetal Heart Rate Patterns on a Cardiotocograph (CTG) to guide bedside assessment, documentation, and the next nursing action.
Nurses must accurately interpret CTG tracings to assess fetal well-being and identify signs of potential distress. The ability to differentiate between benign and non-reassuring patterns is a critical skill.
Recognizing early decelerations as a benign response to head compression prevents unnecessary anxiety and interventions, allowing labor to progress normally.
Distinguishing early decelerations from non-reassuring patterns like late decelerations (indicating placental insufficiency) or severe variable decelerations (indicating cord compression) is crucial for timely intervention to prevent fetal compromise.

How to Approach the Question

First, examine the top tracing, which represents the Fetal Heart Rate (FHR). Determine the baseline rate (the average rate between contractions), which is within the normal 110-160 bpm range here.
Next, examine the bottom tracing, which shows uterine contractions. Note their frequency, duration, and peak.
Correlate the changes in the FHR with the uterine contractions. Observe the timing: does the FHR dip start with the contraction, after it, or at a variable time?
In this image, the FHR dip begins and ends with the contraction, and its lowest point (nadir) matches the contraction's peak. This is a 'mirror image' pattern.
Recognize this specific mirror-image pattern as an 'early deceleration'.
Evaluate the options. 'Fetal deceleration' is the correct category for this pattern. While it is a 'reassuring pattern', that is an interpretation, not the name of the wave itself.

Concept Tested & Keywords

Concept Tested: Interpretation of Fetal Heart Rate Patterns on a Cardiotocograph (CTG)
Stem keywords: Pregnant woman, monitored, nurse, image, wave pattern
Lead-in keywords: Identify
Clinical cues: The visual CTG tracing shows a mirror-image relationship between FHR dips and uterine contractions.

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E6 Midwifery Obstetrics and Gynecology Nursing Sandeep Kaur p. 46-54